Stainless steel is the icon of cleanliness for home and
commercial kitchens, restaurants, hospitals and other settings, but it can
collect disease-causing bacteria like other surfaces if not cleaned often.
Scientists now are reporting discovery, in the ACS journal Langmuir, of a
practical way to make stainless steel that disinfects itself.

Christophe Detrembleur and colleagues explain that while
stainless steel is prized for its durability, resistance to corrosion and ease
of cleaning, it readily collects bacteria over time. The bacteria can form
invisible colonies or biofilms – collections of colonies bound tightly to a
surface – that spread disease. Existing ways of making stainless steel with an
antibacterial surface are complicated, expensive and require the use of
potentially toxic chemical substances. The authors sought an easier,
"greener" way to make an antibacterial coating for stainless steel.

They describe development of a process for giving stainless
steel a coating that killed all E. coli bacteria present within two hours in
laboratory tests. It involves applying a layer of a bio-inspired adhesive to
the steel, then four alternating layers of a negatively-charged polymer and
positively-charged polymer micelles containing silver-based particles, which
are highly bactericidal. The process takes only 10 minutes and uses water
instead of potentially toxic substances. "This novel water-based approach
is convenient, simple and attractive for industrial applications," the
researchers say.